CoreResourceManagementTestCase tests of composites are broken

CoreResourceManagementTestCase was broken when it was moved from full to core. A number of tests are testing adds of /host=x/server=y/subsystem=io/worker=default:add but these tests are bogus:

1) The worker already exists in the profile used by the DC.
2) The params passed to the add op are bogus (leftovers from the 'full' test that tested the threads subsystem.

The tests are primarily checking for failures but these issues mean they can be falsely passing; passing due to failures unrelated to what the test is checking.